Coupling having angularly oriented cavity

ABSTRACT

A coupling for joining pipe elements in end to end relation is disclosed. The coupling includes interconnectable coupling segments having connection members at opposite ends. The connection members are tightenable for drawing the segments toward one another and into engagement with the pipe elements. Each segment has a concavity positioned between inwardly projecting arcuate surfaces that engage grooves in the pipe elements. The concavities house a sealing member that extends circumferentially around the pipe elements. Angularly oriented surfaces are positioned adjacent to the connection members. The surfaces on facing segments engage one another and cause the segments to rotate in opposite directions about an axis perpendicular to the pipe elements. The concavities are angularly oriented with respect to the axis so that when the segments rotate, the cavities receive the sealing member without distorting it. A method of joining pipe elements end to end is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.60/730,305, filed Oct. 26, 2005.

FIELD OF THE INVENTION

This invention relates to mechanical couplings for joining pipe elementstogether in end-to-end relation.

BACKGROUND OF THE INVENTION

Mechanical pipe couplings are used throughout a broad spectrum ofindustry, for example, in mining, petroleum extraction and refining,chemical production as well as in fire protection systems used in officebuildings, warehouses, schools and the like. Mechanical couplingsprovide significant advantages over other methods of joining pipeelements together, for example, welding or brazing, in that they allowfor the assembly of a fluid carrying piping network by relativelyunskilled labor using simple tools. The term “pipe elements” is usedherein to denote any pipe-like item or component having a pipe-likeform. Pipe elements include pipe stock, pipe fittings such as elbows,caps and tees as well as fluid control components such as valves,reducers, strainers, restrictors, pressure regulators and the like.

FIG. 1 shows an example of a mechanical pipe coupling 10 according tothe prior art. Coupling 10 comprises two (or more) segments 12 and 14that are positionable straddling a sealing member 16 and pipe elements18 and 20. Each coupling segment 12 and 14 has arcuate surfaces 22 and24 that respectively engage the pipe elements 18 and 20 to secure themin end to end relation. In the example shown in FIG. 1, the arcuatesurfaces 22 project radially inwardly and engage grooves 26 in the endsof the pipe elements. Other examples include pipe elements having smoothends, flared ends or raised shoulders that are engaged by the couplings.

The sealing member 16 engages both pipe elements 18 and 20 and ensures afluid-tight joint. Sealing member 16 is preferably a flexibleelastomeric ring that is positioned within a cavity 28 within thecoupling defined by a pair of sidewalls 30 and 32 attached to a backwall 34. Sealing member 16 is compressed into engagement with the pipeelements by contact with the sidewalls and back wall of the couplingsegments 12 and 14 as the segments are drawn together to form the pipejoint.

As shown in FIGS. 2 and 3, coupling segments 12 and 14 may haveangularly oriented surfaces 36 and 38 positioned at opposite ends. Theslopes of the surfaces are oriented opposite to one another on eachsegment. When the surfaces on two segments are positioned in facingrelation, as when the segments are straddling pipe elements 18 and 20,and the segments are drawn together, sliding engagement of the surfacescauses the segments to rotate in opposite directions relatively to oneanother about an axis 40 that is oriented substantially perpendicular tothe longitudinal axis 42 of pipe elements 16 and 18. The relativerotation of the segments 12 and 14 is desirable because it forces thearcuate surfaces 22 and 24 into engagement with the side surfaces ofgrooves 26 in the pipe elements and adds rigidity to the joint about allaxes, i.e., bending and torsion, as well as preventing axial expansionor contraction.

In addition to the angularly oriented surfaces described herein, thereare other means for effecting relative rotation of the couplingsegments, such as the crescent shaped protrusion interfitting within thecrescent shaped groove as disclosed in U.S. Pat. No. 5,246,257, herebyincorporated by reference, or the use of offset apertures in attachmentflanges as disclosed in U.S. Pat. No. 4,861,075, also herebyincorporated by reference.

To connect segments 12 and 14, each segment has connection memberspositioned at opposite ends of the segments. In the example illustratedin FIGS. 2 and 3, the connection members comprise projections 44 in theform of lugs that extend outwardly from the segments. The projectionshave apertures 46 that receive fasteners such as bolts 48 and nuts 50which, when tightened, cause the segments 12 and 14 to be drawn towardone another.

While it is advantageous in certain circumstances to increase therigidity of the joint by rotating the coupling segments about axis 40,this rotation of the segments deforms the sealing member 16 through itsengagement with the sidewalls 30 and 32. It is preferable not to distortthe shape of the sealing member through rotation of the segments.

SUMMARY OF THE INVENTION

The invention concerns interconnectable pipe coupling segments, eachpositionable straddling a sealing member and end portions of a pair ofpipe elements engaged with the sealing member for securing the pipeelements together in end-to-end relationship. Each segment comprises apair of arcuate surfaces adapted to interface with the outer surfaces ofthe pipe elements. First and second connection members are positioned atopposite ends of the arcuate surfaces for adjustably connecting onecoupling segment to another. The connection members are adjustablytightenable for drawing the segments together. First and secondangularly oriented surfaces are positioned adjacent to the first andsecond connection members respectively. The angularly oriented surfaceshave opposite slopes. The angularly oriented surfaces on one segment arepositionable in facing relation with angularly oriented surfaces onanother segment and engage one another when the segments are drawntogether. Engagement of the surfaces causes the segments to rotaterelatively to one another about an axis oriented substantiallyperpendicularly to the pipe elements. A concavity is positioned betweenthe arcuate surfaces and extends circumferentially around the segment.The concavity is oriented angularly with respect to the axis to receivethe sealing member. In another embodiment, the cavity is divided into aplurality of sectors, at least one of the sectors being orientedangularly with respect to the axis. In a particular embodiment, thesegment has three sectors, two of which are located at opposite ends ofthe segment. These two sectors are angularly oriented with respect tothe aforementioned axis.

The invention also includes a pipe coupling positionable straddling asealing member and end portions of a pair of pipe elements for securingthe pipe elements together in end-to-end relationship. The pipe couplingcomprises a pair of the coupling segments as described above.

The invention further includes a method of securing facing end portionsof pipe elements together in end-to-end relationship. The methodcomprises:

-   -   (a) providing a pipe coupling having a pair of coupling segments        attached to one another end-to-end, the coupling segments each        having arcuate surfaces adapted to interface with the outer        surfaces of the pipes, the coupling segments each having a        concavity positioned between the arcuate surfaces and extending        circumferentially around the segments, the concavity being        adapted to receive a sealing member, the concavity being        oriented angularly with respect to an axis oriented        substantially perpendicular to the pipe elements;    -   (b) positioning the end portions of the pipe elements between        the segments;    -   (c) drawing the coupling segments into engagement with the outer        surfaces of the pipe elements;    -   (d) rotating the coupling segments in opposite directions about        the axis relatively to one another thereby orienting the        cavities substantially perpendicular to the pipe elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a pipe joint using a pipecoupling according to the prior art;

FIG. 2 is an exploded perspective view of a pipe coupling according tothe prior art;

FIG. 3 is an exploded side view of the pipe coupling shown in FIG. 2;

FIG. 4 is a front view of a pipe coupling segment according to theinvention;

FIG. 5 is a bottom view of the pipe coupling segment shown in FIG. 4;

FIG. 6 is a front view of another embodiment of a pipe coupling segmentaccording to the invention; and

FIG. 7 is a bottom view of the pipe coupling segment shown in FIG. 6.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIGS. 4 and 5 show a pipe coupling segment 52 according to theinvention. Segment 52 has arcuate surfaces 54 and 56 adapted tointerface with the outer surfaces of pipe elements. A cavity 58 ispositioned between the arcuate surfaces. The cavity is defined bysidewalls 60 and 62 and a back wall 64 attached to the sidewalls.Angularly oriented surfaces 66 and 68 are positioned at each end of thecoupling segment. The surfaces 66 and 68 have opposite slopes, and whenthey engage similar surfaces on another segment in facing relation theycause the coupling segments to rotate in opposite directions relativelyto one another about an axis 70 that is substantially perpendicular tothe longitudinal axis of the pipe elements being joined by the coupling.Connection members 72 and 74 are positioned at opposite ends of thecoupling segment 52. In this example the connection members compriselugs having apertures 76 adapted to receive fasteners such as bolts andnuts for connection of two coupling segments together straddling pipeelements.

In the embodiment shown in FIGS. 4 and 5, cavity 58 has an angularorientation with an orientation angle 78 measured about the rotationaxis 70 relative to a datum line 80 that extends between the connectionmembers 70 and 72. The orientation angle 78 of cavity 58 is defined bythe angle 82 of the sidewalls 60 and 62 relative to a line 81 parallelto the datum line 80. Orientation angle 78 is preferably less than 4°for practical designs, and may range between ¼° and 4° depending uponthe coupling size and degree of rotation of the coupling segments. Theorientation angle 78 is oriented in a direction opposite to that of thedirection of relative rotation of the coupling segment 52 when engagedwith another coupling segment. This arrangement of the orientation anglecompensates for the rotation of the coupling segment so that the sealingmember, which is substantially perpendicular to the longitudinal axis ofthe pipe elements (i.e., aligned with datum line 80), is not distortedby interaction with the sidewalls 60 and 62 and back wall 64 when thecoupling segment rotates about axis 70. Cavity 58 is, thus, angled sothat, despite the fact that the coupling segments rotate relative to thepipe elements and the sealing member, the sealing member is receivedsubstantially squarely within the cavity and is not distorted by forcedcontact with one of the sidewalls as a result of the rotation.

When coupling segments 52 are attached to one another surrounding asealing member and pipe elements in a manner similar to that shown inFIGS. 1 and 2, they will be initially skewed in opposite directions dueto the sidewalls of the cavities engaging the sealing member, thecavities being angularly oriented as described above. As the segmentsare brought towards the pipe elements, the arcuate surfaces 54 and 56may not initially align with the grooves in the pipe elements due to theinitial skew of the segments. As a result, the arcuate surfaces may notproperly engage the grooves. To lessen the chance of such misalignment,it is advantageous to chamfer the outer regions 83 of the arcuatesurfaces 54 and 56 where they are expected to make first contact withthe grooves in the pipe elements.

In another coupling segment embodiment 84, shown in FIGS. 6 and 7, thecavity 86 is divided into a plurality of sectors. In this example, thereare three sectors, two end sectors 88 and 90 positioned at opposite endsof segment 84, and a middle sector 92 positioned between the endsectors. When three sectors are present, it is advantageous that eachend sector subtend an angle 94 of about 45° and the middle sectorsubtend an angle 96 of about 90°. Other angular distributions are alsofeasible.

The end sectors 88 and 90 of cavity 86 are differentiated from themiddle sector 92 by their angular orientation. Preferably, the endsectors 88 and 90 have respective orientation angles 98 and 100 lessthan about 6° and more preferably between about ¼° and about 6° whilethe middle sector 92 is not angularly oriented as defined herein.Preferably, the orientation angles 98 and 100 of the end sectors havethe same magnitude and slope.

The coupling segments are preferably cast from ductile iron but couldalso be molded in plastic or machined from a metal billet. It isadvantageous to impart the angular orientation of the cavity duringcasting of the segments rather than by machining after casting. Theconfiguration having a plurality of sectors provides advantages in thepreparation of the pattern for casting of the coupling segment. This isespecially advantageous for couplings which deform to conform with theshape of the pipe elements. Because the linear motion of the segmentsduring rotation about axis 70 is greatest at each end, it is feasible toangularly orient only the end sectors and leave the middle sectorunaffected. The relatively limited traversal of the middle sector tendsto have less distorting effect on the sealing member than the endsectors, which traverse the greater distance upon rotation by virtue oftheir greater distance from the axis of rotation.

Although the example couplings shown herein have two segments andangularly oriented surfaces to effect relative rotation of the segments,the angularly oriented cavity is applicable to prevent sealing memberdistortion in any style coupling wherein the segments are rotatedrelatively to one another out of the plane of the coupling. Furtherexamples include couplings having 4 or more segments as well ascouplings having different means for effecting relative rotation.

1. Interconnectable pipe coupling segments, each positionable straddlinga sealing member and end portions of a pair of pipe elements engagedwith said sealing member for securing said pipe elements together inend-to-end relationship, wherein each said segment comprises: a unitarybody comprising a pair of arcuate surfaces adapted to interface with theouter surfaces of said pipe elements; first and second essentiallyplanar faces oriented parallel to one another and positioned in spacedrelation to each other on opposite sides of said unitary body, each ofsaid essentially planar faces being positioned adjacent to one of saidarcuate surfaces; first and second connection members positioned atopposite ends of said arcuate surfaces for adjustably connecting onecoupling segment to another, said connection members being adjustablytightenable for drawing said segments together; and a concavityextending entirely between end faces of said segment and positionedbetween said arcuate surfaces and extending along an inner circumferenceof said segment, said concavity being oriented angularly with respect tosaid arcuate surfaces about a first axis oriented substantiallyperpendicular to a second axis that extends between said first andsecond connection members of one of said segments, said angularorientation of said concavity being measured with respect to a datumline positioned between and oriented substantially parallel to saidfirst and second essentially planar faces.
 2. A pipe couplingpositionable straddling a sealing member and end portions of a pair ofpipe elements for securing said pipe elements together in end-to-endrelationship, said pipe coupling comprising: first and second couplingsegments, each coupling segment comprising a unitary body having a pairof arcuate surfaces adapted to interface with the outer surfaces of saidpipe elements; first and second essentially planar faces orientedparallel to one another and positioned in spaced relation to each otheron opposite sides of said unitary body, each of said essentially planarfaces being positioned adjacent to one of said arcuate surfaces; firstand second connection members positioned at opposite ends of saidarcuate surfaces for adjustably connecting one coupling segment toanother, said connection members being adjustably tightenable fordrawing said segments together; and a concavity extending entirelybetween end faces of each respective coupling segment and positionedbetween said arcuate surfaces and extending along an inner circumferenceof said segment, said concavity being oriented angularly with respect tosaid arcuate surfaces about a first axis oriented substantiallyperpendicular to a second axis that extends between said first andsecond connection members of one of said segments, said angularorientation of said concavity being measured with respect to a datumline positioned between and oriented substantially parallel to saidfirst and second essentially planar faces.
 3. A pipe couplingpositionable straddling a sealing member and end portions of a pair ofpipe elements for securing said pipe elements together in end-to-endrelationship, said pipe coupling comprising: first and second couplingsegments, each coupling segment comprising a unitary body having a pairof arcuate surfaces adapted to interface with the outer surfaces of saidpipe elements; each said coupling segment having first and secondessentially planar faces oriented parallel to one another and positionedin spaced relation to each other on opposite sides of said unitary body,each of said essentially planar faces being positioned adjacent to oneof said arcuate surfaces; each coupling segment having first and secondconnection members positioned at opposite ends of said arcuate surfacesfor adjustably connecting one coupling segment to another, saidconnection members being adjustably tightenable for drawing saidsegments together; each coupling segment having first and secondangularly oriented surfaces respectively positioned adjacent to saidfirst and second connection members on each said segment, said firstangularly oriented surface on each segment having a slope opposite tosaid second angularly oriented surface, said angularly oriented surfaceson said first segment being positioned in facing relation with angularlyoriented surfaces on said second segment and engaging one another whensaid segments are drawn together and causing said segments to rotaterelatively to one another about a first axis oriented substantiallyperpendicular to a second axis that extends between said first andsecond connection members of one of said segments; and each couplingsegment having a concavity extending entirely between said first andsecond angularly oriented surfaces of each coupling segment andpositioned between said arcuate surfaces and extending along an innercircumference of said segment, said concavity being divided into aplurality of sectors, at least one of said sectors being orientedangularly with respect to said arcuate surfaces about said first axisand said angular orientation of said concavity being measured withrespect to a datum line positioned between and oriented substantiallyparallel to said first and second essentially planar faces.
 4. A pipecoupling according to claim 3, wherein said concavity is divided intofirst and second end sectors respectively positioned adjacent toopposite ends of said segment, and a middle sector positioned betweensaid end sectors, said end sectors being oriented angularly about saidfirst axis with respect to said datum line.
 5. A pipe coupling accordingto claim 3, wherein said end sectors each subtend an angle of 45° andsaid middle sector subtends an angle of 90° said angles being measuredfrom a center of curvature of one of said arcuate surfaces.
 6. A pipecoupling according to claim 3, wherein said end sectors are angularlyoriented at an orientation angle less than 6° measured relatively tosaid datum line.
 7. A pipe coupling according to claim 3, wherein saidend sectors are angularly oriented at an orientation angle between ¼°and 6° relatively to said datum line.
 8. Interconnectable pipe couplingsegments, each positionable straddling a sealing member and end portionsof a pair of pipe elements engaged with said sealing member for securingsaid pipe elements together in end-to-end relationship, wherein eachsaid segment comprises: a unitary body having a pair of arcuate surfacesadapted to interface with the outer surfaces of said pipe elements;first and second essentially planar faces oriented parallel to oneanother and positioned in spaced relation to each other on oppositesides of said unitary body, each of said essentially planar faces beingpositioned adjacent to one of said arcuate surfaces; first and secondconnection members positioned at opposite ends of said arcuate surfacesfor adjustably connecting one coupling segment to another, saidconnection members being adjustably tightenable for drawing saidsegments together; means for rotating said segment in a first directionabout a first axis oriented substantially perpendicular to a second axisthat extends between said first and second connection members; and aconcavity extending entirely between end faces of the segment andpositioned between said arcuate surfaces and extending along an innercircumference of said segment, said concavity being oriented angularlywith respect to said arcuate surfaces about said first axis and saidangular orientation of said concavity measured with respect to a datumline positioned between and oriented substantially parallel to saidfirst and second essentially planar faces.
 9. Interconnectable pipecoupling segments according to claim 8, wherein said concavity isoriented angularly at an orientation angle less than 4° measuredrelatively to said datum line.
 10. Interconnectable pipe couplingsegments according to claim 8, wherein said concavity is orientedangularly at an orientation angle between ¼° and 4° measured relativelyto said datum line.
 11. Interconnectable pipe coupling segmentsaccording to claim 8, wherein said concavity is angularly oriented in asecond direction about said first axis, said second direction beingopposite to said first direction.
 12. Interconnectable pipe couplingsegments according to claim 8, wherein said concavity comprises firstand second sidewalls positioned in spaced relation to one another and aback wall attached to said sidewalls.
 13. Interconnectable pipe couplingsegments according to claim 8, wherein said connection members comprisea pair of projections extending outwardly from the ends of each of saidsegments, said projections being adapted to receive fasteners foradjustably connecting said segments to one another, said fasteners beingadjustably tightenable for drawing said arcuate surfaces of saidsegments together into engagement with said outer surfaces of said pipeelements.
 14. Interconnectable pipe coupling segments according to claim8, wherein at least one of said projections comprises a lug having anaperture therethrough adapted to receive said fastener. 15.Interconnectable pipe coupling segments according to claim 8, whereinsaid means for rotating comprises first and second angularly orientedsurfaces positioned adjacent to said first and second connection memberson each said segment respectively, said first angularly oriented surfacehaving a slope opposite to said second angularly oriented surface oneach said segment, said angularly oriented surfaces on one said segmentbeing positionable in facing relation with said angularly orientedsurfaces on another said segment and engaging one another when saidsegments are drawn together and causing said segments to rotaterelatively to one another about said first axis.
 16. Interconnectablepipe coupling segments according to claim 8, wherein said arcuatesurfaces project radially inwardly.
 17. Interconnectable pipe couplingsegments according to claim 16, wherein said arcuate surfaces aresubstantially continuous along said segments.
 18. A pipe couplingpositionable straddling a sealing member and end portions of a pair ofpipe elements for securing said pipe elements together in end-to-endrelationship, said pipe coupling comprising: first and second couplingsegments, each coupling segment comprising a unitary body having a pairof arcuate surfaces adapted to interface with the outer surfaces of saidpipe elements; each coupling segment having first and second essentiallyplanar faces oriented parallel to one another and positioned in spacedrelation to each other on opposite sides of each of said unitary bodies,each of said essentially planar faces being positioned adjacent to oneof said arcuate surfaces; each said coupling segment having first andsecond connection members positioned at opposite ends of said arcuatesurfaces for adjustably connecting one coupling segment to another, saidconnection members being adjustably tightenable for drawing saidsegments together; each said coupling segment having means for rotatingsaid first segment in a first direction and said second segment in asecond direction relatively to one another about a first axis orientedsubstantially perpendicular to a second axis that extends between saidfirst and second connection members of one of said segments, said firstdirection being opposite to said second direction; and each saidcoupling segment having a concavity extending entirely between end facesof each coupling segment and positioned between said arcuate surfacesand extending along an inner circumference of each of said segments,each of said concavities being oriented angularly with respect to saidarcuate surfaces about said first axis and said angular orientation ofsaid concavity measured with respect to a datum line positioned betweenand oriented substantially parallel to said first and second essentiallyplanar faces.
 19. A pipe coupling according to claim 18, wherein atleast one of said concavities is oriented at an orientation angle lessthan 4° measured relatively to said datum line.
 20. A pipe couplingaccording to claim 18, wherein at least one of said concavities isoriented angularly at an orientation angle between ¼° and 4° measuredrelatively to said datum line.
 21. A pipe coupling according to claim18, wherein said concavity of said first coupling segment is angularlyoriented in said second direction about said first axis and saidconcavity of said second coupling segment is angularly oriented in saidfirst direction about said first axis.
 22. A pipe coupling according toclaim 18, wherein said concavity comprises first and second sidewallspositioned in spaced relation to one another and a back wall attached tosaid sidewalls.
 23. A pipe coupling according to claim 18, incombination with said sealing member, said sealing member comprising aflexible, resilient seal, said seal being a substantially circular ringhaving an inner diameter, said seal being positioned within saidconcavities of said first and second coupling segments.
 24. A pipecoupling according to claim 18, wherein said means for rotatingcomprises first and second angularly oriented surfaces respectivelypositioned adjacent to said first and second connection members on eachsaid segment, said first angularly oriented surface having a slopeopposite to said second angularly oriented surface on each said segment,said angularly oriented surfaces on said first segment being positionedin facing relation with said angularly oriented surface on said secondsegment and engaging one another when said first and second segments aredrawn together and causing said first and second segments to rotaterelatively to one another about said first axis.
 25. A pipe couplingaccording to claim 18, wherein said arcuate surfaces project radiallyinwardly.
 26. A pipe coupling according to claim 25, wherein saidarcuate surfaces are substantially continuous along said segments.
 27. Apipe coupling according to claim 18, wherein said connection memberscomprise a pair of projections extending outwardly from the ends of eachof said segments, said projections being adapted to receive fastenersfor adjustably connecting said segments to one another, said fastenersbeing adjustably tightenable for drawing said segments together.
 28. Apipe coupling according to claim 27, wherein at least one of saidprojections comprises a lug having an aperture therethrough adapted toreceive said fastener.
 29. Interconnectable pipe coupling segments, eachpositionable straddling a sealing member and end portions of a pair ofpipe elements engaged with said sealing member for securing said pipeelements together in end-to-end relationship, wherein each said segmentcomprises: a unitary body having a pair of arcuate surfaces adapted tointerface with the outer surfaces of said pipe elements; first andsecond essentially planar faces oriented parallel to one another andpositioned in spaced relation to each other on opposite sides of saidunitary body, each of said essentially planar faces being positionedadjacent to one of said arcuate surfaces; first and second connectionmembers positioned at opposite ends of said arcuate surfaces foradjustably connecting one coupling segment to another, said connectionmembers being adjustably tightenable for drawing said segments together;first and second angularly oriented surfaces positioned adjacent to saidfirst and second connection members respectively, said first angularlyoriented surface having a slope opposite to said second angularlyoriented surface, said angularly oriented surfaces on one said segmentbeing positionable in facing relation with angularly oriented surfaceson another said segment and engaging one another when said segments aredrawn together and causing said segments to rotate relatively to oneanother about a first axis oriented substantially perpendicular to asecond axis that extends between said first and second connectionmembers of one of said segments; and a concavity extending entirelybetween said first and second angularly oriented surfaces of eachcoupling segment and positioned between said arcuate surfaces andextending along an inner circumference of said segment, said concavitybeing divided into a plurality of sectors, at least one of said sectorsbeing oriented angularly with respect to said arcuate surfaces aboutsaid first axis and said angular orientation of said concavity measuredwith respect to a datum line positioned between and orientedsubstantially parallel to said first and second essentially planarfaces.
 30. Interconnectable pipe coupling segments according to claim29, wherein said concavity is divided into first and second end sectorsrespectively positioned adjacent to opposite ends of said segment, and amiddle sector positioned between said end sectors, said end sectorsbeing oriented angularly about said first axis with respect to saiddatum line.
 31. Interconnectable pipe coupling segments according toclaim 30, wherein said end sectors each subtend an angle of 45° and saidmiddle sector subtends an angle of 90° , said angle being measured froma center of curvature of one of said arcuate surfaces. 32.Interconnectable pipe coupling segments according to claim 30, whereinsaid end sectors are oriented at an orientation angle less than 6°measured relatively to said datum line.
 33. Interconnectable pipecoupling segments according to claim 30, wherein said end sectors areoriented angularly at an orientation angle between ¼° and 6° measuredrelatively to said datum line.